Really beautiful image! I love the background colors, especially the sky. I love the detail in the moon as well as the stars down by the trees.
The one thing that really stands out to me is the head. Up to where the eye is, it looks like a profile shot, but the turn of the muzzle makes it look like a 3/4 view. It looks very awkward.
Overall the moon looks absolutely gorgeous, however the sky and trees look fairly realistic. This part may just be my preference for details to blend a little more, but it stands our a bit more than the rest of the background. Maybe, sharpen some of the details there and tone down the glowing.
Also, the glow around the wolf's body makes it stand out too much from the overall image. The glow around the head and ears is good because that's where the light of the moon is coming from, however it should fade near the neck.
But this is a very gorgeous image.